Various types of electrosurgical endoscopic medical and surgical instruments are known in the art. These instruments typically include an elongated insulated instrument tube which houses an elongate manipulator shaft which is axially reciprocable within the tube by means of a handle or trigger-like actuating means. An end effector or surgical tool such as, for example, a forceps, a gripper, or a cutter, is coupled to the distal end of the manipulator shaft by a linkage which translates the axial movement of the shaft into a desired movement of the end effector.
As a result of the use of such instruments, it is normal for tissue or body fluid to be deposited upon and between any one of the various parts of the instrument including the tube, the shaft, the end effector, and its associated linkages. Some of such instruments known in the art include a "take-apart" shaft incorporating a yoke which allows the shaft to be disconnected and removed from the tube for sterilization and cleaning.
The present invention provides an improved yoke for coupling an end effector with its manipulator shaft which allows a user to simply and smoothly secure and remove the manipulator shaft from the instrument tube so that the shaft can be cleaned and sterilized separately from the tube or, alternatively, to allow the user to simply and quickly substitute different end effectors in the same instrument.